NavWeek: Speed Quest

No

Tue, 2014-07-01 21:07

As the U.S. Navy revisits many of the requirements for its Littoral Combat Ship (LCS), it’s certainly time to reconsider the vessel’s need-for-speed concept. There is no question the Navy needs a fast ship for some of the proposed LCS missions –- the issue is just how fast the ship needs to go, and what is the service willing to give up for the ability to zip across the seas? Alternately, perhaps the Pentagon should consider a whole new vessel as its maritime sprinter.

Officially, the LCS goes above 40 knots. When I was on LCS 1 USS Freedom last year, the ship was pushing it near 50, leaving any questions about its speed-demon status well in its wake.

Now, with Defense Secretary Chuck Hagel’s directive to make the LCS successor more lethal and survivable, Navy officials say they can dial that speed back a bit. But how much? The low 40s? High 30s. Mid-30s?

Navy officials will most certainly review Freedom deployment data from its Singapore swing last year before deciding that number. But they also should review –- and I’d like to think they would actually be re-reviewing -– some earlier reports on this Navy speed quest and the results thus far.

“The pursuit for high speed itself demonstrates an inherent bias toward the attribute of speed and the neglect of range and payload requirements,” writes David Rudko in his March 2003 thesis, “Logistical Analysis of the Littoral Combat Ship,” prepared for the Naval Postgraduate School at Monterey, Calif.

“Ideally, a small warship would be inexpensive and fast, carry a large payload and have high endurance and good sea keeping,” he writes in the published thesis. “Unfortunately, the current state of technology prevents this combination.”

He notes, “Throughout history, the United States Navy has invested a considerable amount of time and money in the development of high-speed ships.” Looking back to the 1960s, he writes, “The Asheville class experienced many problems throughout its life cycle. In the design process, the tradeoff between speed, payload and range was a great source of debate and resulted in delayed construction. Each ship cost approximately $5 million, five times greater than the initial $1 million projection, and high maintenance costs made them expensive to operate once commissioned. Additionally, sea keeping problems prevented them from capitalizing on the high speeds for which they were designed. The changes in missions they experienced throughout their service life demonstrated their inability to successfully fulfill the primary mission for which they were designed.”

Then came the Pegasus class missile hydrofoils. “The initial concept was to establish a squadron of missile hydrofoils, each carrying a different modular weapons package, capable of functioning collectively as one multi-mission conventional warship.”

He points out, “Due to the inability to incorporate a modular weapons capability into the missile hydrofoil design, the squadron concept never came to fruition and the missile hydrofoil’s limited role was not in keeping with the Navy’s emphasis on multi-purpose ships that were more adaptable to the full spectrum of naval operations.”

He says, “The more appropriate question is whether or not it is possible to overcome the limitations which have, throughout history, prevented previous high-speed ship designs from successfully capitalizing on any value that speed potentially offers.”

Rudko is not the only one to raise such questions. “Persistence in the quest for speed has involved hundreds if not thousands of scientists and engineers over many decades dedicated to developing new ship and vehicle technology to give the Navy credible high-speed options,” say Dennis Clark, William Ellsworth, and John Meyer in their 2004 report for the U.S. Navy’s Surface Warfare Center, Carderock Division, “The Quest for Speed at Sea.”

They write of the focus after World War II, “when the U.S. Navy began to seriously consider the value of proposed concepts for planing craft, multihulls, hydrofoils, hovercraft, and hybrids,” noting, “In the period 1970 to 1983, 327 fast attack units and 1,471 patrol craft were constructed and exported worldwide. Their excellent cost-effectiveness ratio, simplicity of operation, miniaturized electronics, and relatively heavy firepower attracted the attention of many navies, particularly those operating in restricted waters. The modern planing hull now has better seakeeping characteristics with little sacrifice in calm water performance.”

In the mid-1970s, they say, “The U.S. Navy undertook an advanced planing hull research program aimed at improving seakeeping while retaining as much speed as possible and improving the lift-to-drag ratio of the hull through the mid-speed range.”

But, they say, “The aggressive and successful planning hull research program initiated in the early 1970s subsided in the late 1970s, when the U.S. Navy decided to emphasize acquisition of large combatants capable of transiting the world’s oceans. With this philosophy, problems can arise when we need to engage in limited warfare in areas where the larger ships cannot operate close to shore, or in the inner harbors or rivers.”

So the Navy pulled back from the research at the time when it really needed to step up such studies. “While many of the high-speed vehicle types described above have been in existence for many years, we have limited experience in their application in actual naval missions,” they report.

Another Carderock report from the Naval Warfare Center, the High-Speed, Small Naval Vessel Technology Development Plan, says, “It is unlikely that the full matrix of technologies will be developed... . Naval high-speed (40 to 60 knots) missions require extrapolation beyond current capabilities in critical areas such as structural loads, resistance and powering, and seakeeping.”

One program that proved, in the end, to be somewhat successful was the Cyclone-class patrol coastal (PC) ship. After essentially being dumped by the Navy -– with some of the ships going to the Coast Guard for a bit -– the vessels now are being used in a variety of missions and getting more lethal weaponry.

But the PCs are even less lethal and survivable than the LCSs. If Navy officials are going to consider those types of ships, it should look at whole new fast-ship concepts, considering different types of seacraft altogether.

“Efforts to solve the seakeeping and ride comfort problems led, in the 1960s, to the small-waterplane-area twin-hull (Swath) ship configuration,” Clark, Ellsworth and Meyer write. “Although the Swath ship is an important development with a number of desirable features, it is not currently considered a high-speed concept.”

There’s a company in Portsmouth, N.H., looking to change that. Juliet Marine Systems has developed a prototype small-attack craft based on the Swath concept that looks something like a sea-skimming F-117 called Ghost that it is touting as a “poor man’s LCS.”

Credit: Juliet Marine Systems

The boats are certainly portable –- you can fit four of them in the well deck of an LPD 17 San Antonio Class amphibious ship.

The U.S. Navy has discussed the vessel with the company, CEO Gregory Sancoff says, but there’s been nothing official. There has, however, been international interest, he says.

“We have had many discussions about building a Corvette-sized Ghost to carry a crew and sophisticated weapons systems and missiles,” he says. “Ghost would be capable of operating in denied-access areas without detection, due to vessel design and by utilizing RAM (radar-absorbing material) coatings.”

He notes, “Ghost today can carry over 80 of Lockheed Martin’s Nemesis missiles in an enclosed weapons bay.”

The boat provides a huge advantage, he says, as missile thrust does not have to be redirected but can vertically exhaust in an effective and safe manner. “Ghost fires the missiles from an enclosed weapons bay and the thrust is directed down between the hulls, hidden from satellites and cooled by the ocean waters. The craft is ideal for missions requiring the ability to fire and sprint.”

Countries like Qatar do not need a destroyer or LCS, he says. “They need smaller tactical platforms that bring all the capabilities of LCS in a smaller package to protect their country and escort exports ships. Ghost can also carry two Mark 48 lightweight torpedoes if necessary.”

Of course, this late in the game, it appears unlikely such a novel concept has a ghost of a chance of being an LCS stand-in for the successor warship missions